


A Warm Body and Heart

by ShounenLomWriter



Category: Fate/Grand Order
Genre: Alternate Universe, Breeding Kink, Brynhildr gives herself a magical dick in this, Double Penetration, Multi, Sex Magic, Size Difference, Threesome - F/M/M, Trans Surtr, i just really like poly relationships
Language: English
Status: Completed
Published: 2021-01-03
Updated: 2021-01-03
Packaged: 2021-03-10 21:40:31
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,721
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28374039
Author URL: https://archiveofourown.org/users/ShounenLomWriter/pseuds/ShounenLomWriter
Summary: Taken place After LB 2, Surtr ends up being summoned by fujimaru. All though he hated being around him and other servants, As he still have urges to destroy the world.Bryn and Sigurd however, decided to show him a different kind of ‘Experience’, one that will leave him  pleasurable.
Relationships: Brynhildr | Lancer/Sigurd | Saber, Brynhildr | Lancer/Sigurd | Saber/Surtr, Sigurd | Saber/Surtr
Comments: 7
Kudos: 1





	A Warm Body and Heart

The summon was...really an unexpected one.

Fujimaru was unsure if he was really THAT lucky or unlucky to summon such a unexpected servant in chaldea.   
  
Mash, Fou, and Fujimaru both looked up in awe and shock at the servant that has just been summoned.

”Servant...Saber and King Of Giants, Surtr, is at your-“

before the giant fire monstrosity could finish talking, Fujimaru quickly yelped at the sight of this giant servant, he was completely confused and concerned on how is it possible. No doubt, he has summoned other giant servants, but this is surtr there looking at, THE king of giants and the same one that nearly tried to kill everyone from the last Lostbelt they just pruned. 

He has now become summonable from some kind of interesting lucky the master had, but there one tiny problem:

Without ophelia around anymore, it seems both Fujimaru and mash’s fears of him acting more dangerous would be a huge problem they thought to themselves, If he remembers her that is.

“Um...excuse me, Master”

The king of giants spoke as the master quickly snapped out of it and looks up at him, he gives off a nervous chuckle.

“o-oh! Sorry! W-Welcome to Chaldea Surtr! I’m Fujimaru Ritsuka” he then moves his hand to mash as he hold her gently, mostly so she doesn’t get harmed hopefully.

”S-Senpai..!” The purple hair pseudo servant blushes softly at the sudden touch.

“And this is Mash Kryielight and her small pet, Fou!”

The small squirrel like creature quickly hides behind Mash’s legs as it looks up at the giant still, seeming to be either afraid or cautious.

”We hope you make yourself at home! Every servant here is family! Also, Do understand that we are here to save humanity, I understand you won’t understand that but...soon you will”

The giant watched the master give off a small smiles. Saving humanity? He finds that to be a stretch as all he wanted to do is to destroy it. But since its his master, he’ll see how everything goes in chaldea.

_____________________________________

Letting such a Giant, evil servant like him is like bringing a giant bomb in a house, they never know when will he snap, and thats what there worried about.   
  
Already, some servants, like Scathach-Skadi and The Valkyries, actually remember him surprisingly, thou the Valkyries tried to throw there spears at him and Skadi literally used runes at him angrily as he slowly tries to walk away, as he meant no harm (yet).

Some other giant servants, like Kingprotea and Paul Bunyan have tried to befriend him, however he seemed to not understand friendship as well as how it works, and his Troubling emotions would sometimes scare them away.

The children servants in chaldea seem to really like Surtr’s company thou, surprisingly, mash has watched him letting the kids roast marshmallows on his flaming hair, they believe he surprisingly has some soft spot to children.

Though everything was slowly starting to make Surtr comfortable in chaldea, there is still one thing that hasn’t changed:

Wanting to destroy the world

Master had constantly told him that he shouldn’t destroy the world, thou half of the servants in chladea think master telling him that is a VERY TERRIBLE idea.

Luckily, Surtr never did it, but he still ask, even at times when master does something or supports him, he can’t understand his gratitude for him, only to destroy the world for Fujimaru.

Fujimaru worries he couldn’t keep this up and worries he will do it one day, that is until the next day.

_____________________________________  
  
“Master, What is the matter?”

Master snapped out of his own thoughts as he Looked up to see who it is.

It was Brynhildr and Sigurd. 

The two tragic lovers seem to wonder if Fujimaru is doing alright, as they noticed him possibly overthinking about something, Brynhildr and Sigurd seemed to be caring around there master ever since the two are finally now together, and mostly for Sigurd to get stabbed by Bryn’s Giant Spear and surviving it, as a way of showing his love for her. They seem to noticed that something is troubling the master.

”Master...you look a bit worried...what is wrong...?” Her soft yet, almost dangerous words seemed to calm the master down a bit as he chuckles a bit.

“Hey you two, It’s fine, i uh..just not too long ago, summoned Surtr and-“ 

He suddenly stopped himself midway, he wasn’t sure if they also remembered what Surtr did back in the previous Lostbelt, he worries that he might’ve opened pandora’s box just by saying his name alone.

”Ah, i see you recently summoned a new servant?” Sigurd replied back in a soft tone, he seemed to be very calmed about this.

“Surtr is it? I see, must’ve been unexpected luck has it master?”

”Surtr...what are you having trouble around him with...master...?”

Brynhildr of course thought if he was hurting the master, she would take matter to her own hands, but luckily Sigurd is around with her this time.

Fujimaru finally spoke

”Well, Since I recently just summoned him, me and mash are worried that he isn’t gonna like Chaldea a lot and well, might start trying to destroy the world for any little thing he hates...” the two seemed to understand Fujimaru’s troubles, and thats when Bryn had a thought.

“Master...What if we help out...?”

both Sigurd and Master looked at her, Fujimaru had a look of concern while Sigurd, a look of curiosity.

”What do you mean by that Brynhildr?”

”We could teach Surtr...human emotions...as well as teaching him about whats in the heart...Even...” 

Brynhildr stop mid sentence as she leans to Sigurd’s ear and whispers to something.

Fujimaru then watched as Sigurd’s Face changed from Calm and Collected to A full on blushing mess, he now wonders what did Bryn said that give him that reaction.

”Alright, i think this can work” Sigurd and Bryn then both looked at Fujimaru as the both smile, like there about to accomplish something.

“Master, you can leave this to us, now, where is Surtr right now?”

_____________________________________  
  
Sigurd and Brynhildr have arrived at the giant king’s room, sigurd was the first to knock at the door, hopefully to get a reply back.

the mechanical doors opened up as the two see Surtr, standing right in front of them at the door. they both noticed how although Surtr looked Big still, he isn’t as the same height as big as the mountain, as he seems to be able to control his own height and size.

“Hello, you must be Surtr, the new servant here correct?” Sigurd looks at him with a almost stern eye contact as he replied back.

”Yes, i’m Surtr, King Of Giants, and who are you two...?”

“Ah! my name is Sigurd and i am a saber class, and this is my lover, Brynhildr, she is a Lancer class” before giving him a short introduction of themselves he quickly noticed his change in behavior.

”A saber class?...hmph, i too am a saber class as well”

”I can see that-“ Sigurd then felt Brynhildr nudging him as he quickly remembered what there here to do.

“Say, is it alright if we come in, just to have a friendly conversation?”   
  
Surtr was cautious at first after hearing those words, he really doesn’t have anything going on him his own room, yet, a conversation wouldn’t actually hurt.

”Alright, come in then..”

Sigurd then hold Brynhildr’s hand as the both walked inside the room just so she doesn’t feel nervous around the fire giant. He wasn’t wrong when said theres nothing special in his room, the only thing that is there is his Flaming Sword perched up against the wall. they can always him decorate the room later anyways.

As the mechanical doors closed, both Bryn and Sigurd sat down on the floor while Surtr was confused, but decided to sit on the bed, thinking this is how conversations work.

”So...What do you think of chaldea here Surtr?” Brynhildr was the first to ask him this as he responded.

”i guess, its alright, most of the kids here used my hair as something to roast marshmallows, but then at least half of them are giants as well, and almost half of the servants here tried to attack me...everything all mighty..it makes me want to destroy this place”

He starts to burn up the room a bit in a short rage, The two lovers now understand Fujimaru’s concerns. they decided to quickly calm him down.

”Say, Surtr, Since we’re having a conversation right now, we want to ask...” 

Sigurd hold onto Brynhildr’s hand as he knows what he is doing. He pushes up his glasses a bit and then spoke.

”Have you ever been in a relationship before, Surtr?”

”Huh? Relationship?” The king of giant wasn’t sure what they where talking about.

”Its like a connection...when two or more people love each other from the heart...they get to understand each other more when in relationships...like me and sigurd...” Brynhildr helped explain to him what a relationship is while Surtr thought about it.

_”Love...? From the heart...?”_

he thought about it while touching his chest, he could only express such emotions by destroying the world...but love? He has never experienced nor understands love.

”Such a type of thing seemed...new to me” before saying that he looked to both the Valkyrie and the Dragon Slayer with a look of surprise.

”So you never experienced it?” Sigurd asked.

”No, i never experienced it, however...” He thought about it for just a while, should he really learn about Relationships as well as Love? A giant like him, wanting to understand things such as emotions.

”I...want you two to teach me about it and help me understand it-“

He watched as the twos eyes gleamed up in excitement, they seemed to be very content about teach him this.   
  


“i’m glad you get to let us help you...being in a relationship will help you a lot Surtr...” she smiled softly as Sigurd adjusted his glasses and smirks.

“We are, i guess you can say, an expert on relationships!” 

Surtr scoffed a bit at there small excitements, and crossed his arms. “Right...then, what do i learn first?”

The two then looked at each other then nodded as they looked back at surtr with a harmless yet concerning smiles which made him a tiny bit worried.

Surtr is unaware what he might put himself into.

_____________________________________

“Hrmm...You sure this is..part of this???”

Surtr was still sitting on the bed, only this time Sigurd and Brynhildr are right beside him.  
  


”Yes, but first i want to give you a Rune spell first...just so none of us get burned badly...”

The Valkyrie isn’t wrong, he is literally a giant of fire, they’ll be burned all over the place if he or the two make one wrong move.

”Done” she smiled as she then sits on the chair and now its just Him and Sigurd. Is she planning to just watch them? the giant was still confused as to what is going on Until he jolted feeling two hands rubbing his shoulders lightly.

”Relax, This is part of what we are gonna show you..” 

Just as he was about to speak, he suddenly felt a strange feeling in his chest, a very strange feeling, he suddenly jolted as he felt the young man’s hand fondling with his horns.  
  


”Ooh, they actually feel pretty smooth and a bit warm, then again the Fire protection rune spell is in affect.” Sigurd kept fondling them as the fire giant hissed quietly at this strange yet soft feeling of his touch.

_”W-what is this...feeling? Is the dragon slayer doing this?? No...i should give in and yet...”_

he looked back at Brynhildr, she is just sitting and watching this unfold, she seems to be alright with this.

”Hey Surtr...all this is new to you correct?” he let one finger stroke the curve of his horns back and forth, giving him a small shiver, Surtr hasn’t said anything yet beside small panting sounds.

”hmm...alright, how about this then?”

”huh? What do you-“   
  
He suddenly got cutoff as the young man turned his face to him and give him a quick kiss in the lips. It was so sudden that Surtr didn’t had time to think.

Its like everything has slow down the minute there lips touched each other, there tounges entwined as one hand hand holds his face while the other still holding to his horns gently and rubbing them.

_”Wha...Whats going on? My head and chest feels funny...and why does my body react differently to it...?”  
_

Sigurd kept moving his tongue up and around his mouth, he was surprised that the fire giant has a tongue as well. Brynhildr blushes a bit but still watches them getting down as sigurd let out a low growling moan in the kiss.

Just as soon as he finally pulled away from the kiss, leaving a bit of drool connecting them, the fire giant seemed to be in such a daze that his face showed a sign of blush that he needed some air before continuing further.

”Well, how was is surtr? have you enjoyed it?”

Surtr still didn’t have time to speak as he was still overwhelmed by the sudden overstimulation as he pant hard.

”hmmm, I think we should keep going, what do you think Brynhildr?”

”Yes, do keep going sigurd...i love to watch..” she spoke with a content smile.

”W-what?-“ he suddenly jolted from the bed as Sigurd starts to slowly lick his neck up and down.

He soon noticed how very sensitive surtr’s neck area is was as he kept licking it more. He let out a little smirk and leans close to him.

”How about i keep this up a lil notch?~”

Sigurd whispered softly before moving both his hands and slowly gropes the giant’s chest area. Thank god for the fire protection spell still in affect, though it still feel warms when licking and groping him while hearing his soft moans.

”Well isn’t that cute, The king of giants must really have a soft spot of sorts~”

He really did like how he mentioned him having a soft spot, however, the more he kept groping and rubbing his chest, it gives off a faint glow.

”Y-you better stop this or i-i will-“

”Hm? You’ll do something?” Sigurd replied.

”You seem to really enjoy this however, that even your chest his glowing, i find that cute actually for a giant~...”

The word ‘cute’ alone makes the Jötunn growling in rage, he wants to kill both the valkyrie and the dragon slayer into a fiery despair, but his sensitive body wouldn’t allow him.

”Theres s-something wrong..” he moaned quietly under his breath. Suddenly he gasped loudly as he quickly looked down as sigurd used his other hand to rub around his groin area while still groping with his other hand.

“W-What are you-Ah!!” He jolted slightly as he tried to cross his legs, but it only made him rub his groin more.

”You wanted to experience this don’t you~? This is what pleasure feels like, you heart and mind has only thought of destruction your whole life...”

He hated how the dragonslayer is right, his whole life all he thought about is to bring destruction and despair to the world, but now his mind feels a bit hazy.

_”I-i will turn you two into a-ashes! I will kill anyone! I-no...why does my heart accept this..?”_

“Ah, Already getting wet?”

Hearing those words, his eyes widen as he looks down and see that he has a cunt.

”W-What is this!?...” he looks only for him to jolt and moan again as sigurd continues to rub his groin more as Bryn watches with amusement.

Every time his fingers rubbed around his lips, more of his juices kept overflowing. Surtr’s moans became more intense by each touch he feels, his whole body starts to become sensitive.   
  


“Sigurd...” she looks at them both as she rubs her legs together, as if she is wants to join in the action too.

”Ah, my beloved, would you like to join in as well?..” he then stops rubbing him as he uses both his hands to life up the fire giant’s legs.   
“you can come here and give him a nice lick~”.

Surtr’s eyes widen in shock as the young man lifted up both his legs with such strength. “S-stop that!” He tried to close his legs until Brynhildr was up close to his groin area.

”a-ah...such a interesting glow and color...” She blushed and panted quietly as both Sigurd and Surtr watched with different expressions.

“Don’t worry, Bryn will be gentle” he gave a soft smile

”W-why you, Unhand me right n- AHHH!”

without warning, a sudden wave of pleasure flowed into his body, it was all so sudden that he let out a small moan out before immediately quieting himself.   
  


The two watched as Brynhildr got to work on using her tongue and licking around the fire jötunn’s clítoris and giving him a Cunnilingius, never in his lifetime this would ever felt this good.

”M-my chest...my b-body...everything feels so warm and strange..” he kept moaning as the Valkyrie kept licking as well as mastrubating herself.

“That means your experiencing more pleasure, your body is allowing it and theres nothing to be ashamed about, Surtr..” 

The sultry whispers suddenly made him feel things in his chest, a strange sensation almost like butterflies inside him. he doesn’t feel ashamed, but doesn’t want to admit it either.

After what felt like an hour, Brynhildr stops as she rubs them, making him moan even more.

”I think he is ready for the next step, sigurd..”

He pants as he looks at them both confused while trying to hide his sudden blushing.

_”R-ready? Ready for what?? What are they talking about??” His thoughts are running around, trying to understand whats going to happen next._

”Alright then” Sigurd then suddenly grabs ahold of Surtr and gently put his head on what he thought was a pillow, that is until he looked up and see’s Bryn, his head was laid on her lap.

He then looked again as Surtr’s eyes widen when he watched him spreading his legs apart then removing his own pants.

He quickly tried to take action before Brynhildr grabbed both his shoulders and couldn’t move his arms, as if there paralyzed.

”Relax, you will enjoy this lots Surtr...very much so..” she give such a calm yet almost threatening sounding voice.

”Why are you always angry?...” Sigurd replied gently.

He growls loudly as he answers back. “I don’t know what are you two doing to me, but you better quit this now!!” he struggles more, trying to break free of her grip, but she seems to be very strong.

Both Bryn and Sigurd looked at each other then back to Surtr.

”Surtr..remember, you did say you wanted to be part of this, did you not?”

He suddenly had nothing to say...yes, it was true, he did agree to this, but it wasn’t what he expected, at the same time his body, emotions, and his mind and been messed with and almost altered in a way, these pleasures that there doing to him did, in fact, feel very different.

The King of Giants Blushes a bit while looking away.   
  


“I..do not want to admit it but, i do enjoy it very much..”

”oh? You enjoyed it?” Sigurd looked a bit surprised, after what felt like minutes have passed by, he smirked slightly as he leans down close to his face. his irritated but nervous face makes him smile.

”Well, we are about to keep going, but once we keep going Surtr, theres no turning back, do you really want this?”

As much as everything thats been suddenly happening to him at chaldea, Surtr wanted to understand pleasurable experience and relationships, he wanted to keep this up. he gulps a bit before blushing again.

”Sigurd, P-Please...Have your throbbing, big member enter inside me so i can be filled up entirely...”

With that, Sigurd got back to business as he continues to remove his pants, his boxers showing a twitching object before removing those as well, showing a completely erect dick. it was huge at size, almost unnatural that even the fire giant was shocked.

Sigurd continued where he left off and spreads his legs again until he slowly leans down, Brynhildr still holding down surtr’s arms.

”Alright...i’m gonna slowly put it in” 

With that, he slowly adjust his member into the entrance with the tip, his entire body reacting to the sudden pleasure, even with just the tip in. He breathed calmly until he kept rubbing the entrance.

”Just relax, everything will be fine” he voice becomes more calming as he slowly pushes his hips completely before he finally stopped as it was fully inside him now.

The room started to spin around him, He shuts his eyes in embarrassment as he blushed and biting his own lip. “It..it hurts..and yet it feels...good?” the giant doesn’t know what else to say, his words and thoughts all melted away from the sudden Pleasure and Ecstasy that slowly the room started to get slowly warm because of his own body heat.

“I’m gonna thrust now, if anything hurts just say ‘stop’, Okay?” Soon, he began to slowly thrust in and out, he was becoming really gently during sex that every moan and gasp become more and more sultry.

_”A-ah...these feelings...why am i having such feelings like this?...my heart feels...warm and beating fast, i’m sweating and everything is spinning...is this what my heart wanted...? Is this...Love and Pleasure?”_

Surtr’s panted harder as he noticed the young man is starting to pick up his thrusting speed slowly.

”Sigurd..looks like he might overheat the entire room at this moment..haa...”

Both Brynhildr and Sigurd started to sweat as the room temperature started to change due to Surtr’s intense literal body heat.

Sigurd the stops thrusting a minute as he starts to remove his clothes while panting still. “Then we might have to undress ourselves then” he smiled at her, hoping to reassure bryn.

She silently nods and the two began to undress until they are both full on naked, afterwards sigurd continued to thrust inside surtr, only this time in a more faster pace.

The Sweat, the intense sex, the heat, everything in the room becomes more and more intense as his moans and intense mana energy filled the room.

“H-Haaah, H-harder...Harder..”

Sigurd jolted a bit as Surtr got up and wrapped his huge arms around his neck and wrapped his legs around his hips as well. Brynhildr puts her hands on both of sigurd’s shoulders as she looks over to him, her breast pressing down on his backside.

”Sigurd, He seem’s to very much enjoy this..” She smiled a bit as Sigurd smiles back at her.

”He sure is Brynhildr, He is enjoying it~” with a small smirk he then begins to quickly thrust again inside him, before long Sigurd turn his head and gave a kiss to Brynhildr and then gasped as he looks at her  
  
“Brynhildr...If you want to make this more exciting, then join me in this fun~”

Brynhildr’s eyes glisten like a happy child after hearing those words, meanwhile Surtr couldn’t tell what there saying anymore, he was so caught up in this lust escapade that his hearing is becoming an Inaudible mess.  
  


Sigurd kept thrusting, holding on to him as he leans in to where his ear would be and whispers while panting under his breath.

”You love this so much don’t you? You wanted to be Breed so badly~? Hnng..”

”B-Breed?...” Suddenly he jolted as he turned his head to see Brynhildr behind him, her breast pressing against his back, as well as something else.

”Sigurd, im very happy to do this along with you~...” Her Huge, Throbbing member was rubbing against his back with a needy anticipation. of course he forgot that they still have the fire protection spells on them, however the room is slowly getting hot that there all sweats from the warm heat.

”I want to Fuck you, i want to fuck you so crazy along with sigurd..” she quickly starts to move her dick to his ass and slowly starts to thrust in him.

The giant’s eyes widen suddenly as he quickly realized what the Valkyrie was about to do.

“W-wait! Not my assho-“ his sentence was cutff midway as there replaced with a loud moan. His entire vision started to become dizzying and blurry, Brynhildr panted softly as she puts her head on his shoulder. 

“Your so warm, i get to thrust into you..Sigurd...Sigurd~!” She yelled out his name with such lustful excitement that without giving some time, she quickly starts to thrust in and out at a fast past along with sigurd, her lustful smile as she enjoyed this ecstasy. There thrust almost in synced as the fire giant becomes less threatening and makes such lewd and needy moans.

_”T-there thrusting in both of my holes...this..this feels so good..the feels so good...I don’t want this to stop”_

The three kept moaning and feeling each other, there lust and ecstasy was on a whole other level, it was something Surtr couldn’t control, he understood what this is...this is what love feels like to him, and he wished this doesn’t end.

”Hnngg...I-I’m gonna cum” Sigurd grunted those words out as he kept thrusting more inside his pussy.

”Ohh! Sigurd, I’m gonna cum too~!” Brynhildr mercilessly thrust harder, that Surtr could’ve sworn he felt her large member almost thrusting into his abdomen. Sigurd then looked at him as he and Brynhildr kept thrusting more and panting hard.

”I’m gonna cum inside your womb~, i want to breed you so bad~!” Such dirty words really does make him turned on fully.

His Fiery heart beating fast from the pleasure as he pants and grips on sigurd’s shoulders to the point he gets scratch marks.

”Cum i-inside me, C-Cum inside me already, i want t-his sweet blissful release~...!”

This is what his heart wanted, To experience new things in chaldea, especially love. this is something he won’t forget.

“I’m Cumming!”

Both Sigurd and Brynhildr thrust one last time until the Three had the most Amazing Orgasm ever, it was such a blissful moment. Surtr panted hard as Brynhildr already pulled out, while sigurd was still inside him.

Sigurd hissed under his breath, each pump of semen filling him up more until the both gave off a sigh of relief. Slowly pulling out until a loud pop can be heard, the three then collapsed in bed as they Try to get a breather from the intense sex they had, and now they felt very exhausted, yet had a very pleasurable experience.   
  


Surtr stared on the ceiling after a while, both Sigurd and Brynhildr looked at him.

”That was a very good experience, was it” Sigurd asked the giant.   
  
Surtr looked exhausted from the intense sex that all he could do was give a thumbs up before passing out completely right in front of them.

”I think we went too rough...” 

”Yeahh..” 

_____________________________________  
  


A Few Weeks have passed, Surtr is slowly but surely getting used to chaldea more, and befriend a few Giant servants like him, not only that, he is now slowly friends with Sigurd and Brynhildr as well.

He still remembered a while back, they they had intense sex as a way to help him understand Emotions and feelings, besides his usual anger and rage, he soon understands the Idea of Love. 

_”Maybe being in chaldea won’t be so_ bad...”

he soon sat with With bryn and sigurd, it might take a while to become friends with them, but they already seemed comfortable around the fire giant already.

maybe, just maybe, he can finally have a second chance here, his new home at chaldea.


End file.
